Apparatus for laying elongate elements

ABSTRACT

Apparatus ( 300, 400 ) for laying an elongate member such as a pipe ( 306 ) or a rail ( 472 ). Material carried by the apparatus is smelted in a furnace ( 340 ) and fed to a casting head ( 342 ) by which the elongate member is continuously cast. The so cast elongate member is then laid by the apparatus, as it travels on the ground surface.

FIELD OF THE INVENTION

This invention relates to apparatus for laying elongate elements.

SUMMARY OF THE INVENTION

In one aspect there is provided apparatus for laying an elongate member, the apparatus having means for continuous forming the elongate member, and means for laying the elongate member as it is formed and as the apparatus travels on a ground surface.

The apparatus may include means for forming molten material and means for forming the elongate member therefrom. The means for forming may form the elongate member by continuous forming. The continuous forming may be effected by continuous casting. The apparatus may have means for storing in flowable the material or at least one component for forming the material in flowable form, such as in granular or particulate form. Means may be provided for delivering the material or said component, in flowable form, to the means for forming molten material, and for delivery thence to the molten material to mould means for casting the elongate member therefrom.

The material from which the elongate member is formed may be metal, and the apparatus for forming may be in the form of a furnace for forming the material as metal, such as by smelting. The apparatus for forming may be a plasma arc furnace.

The elongate member may for example be a pipe, cable or the like, and the apparatus may have excavating means for forming a trench into which the elongate member is in use of the apparatus laid. The elongate member may be a rail, and the apparatus may be arranged to lay the rail forwardly of the apparatus, so that the apparatus may travel on the rail during laying.

In another aspect, the invention provides a method of laying an elongate member, wherein the elongate member is continuously formed on a transport vehicle, and laid by the transport vehicle as the transport vehicle travels.

The method may include forming material in molten form and forming the elongate member by casting of the molten material. The elongate member may be continuously cast. The material, or at least one component for forming the material, may be stored in particulate or other flowable solids form on the transport vehicle, prior to causing the material to be formed in the molten state. The molten material may be delivered to a casting head to form the elongate member therefrom by a continuos casting process.

The molten material may be metal, which may be formed by smelting, such as in a plasma arc furnace.

The elongate member may for example be a pipe, cable, rail or the like.

The method may include excavating, by an excavator on the transport vehicle, to form a trench into which the elongate member is laid. Where the elongate member is a rail, the rail may be laid forwardly of the vehicle, and the vehicle may travel on rail so laid.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way example only with reference to the accompanying drawings in which:

FIG. 1 is a side view of an apparatus constructed in accordance with the invention;

FIG. 2 is a scrap vertical section of part of the apparatus for receiving, holding and transferring raw materials to a furnace incorporated into the apparatus;

FIG. 3 is a scrap vertical section of a rotary kiln for transferring raw material to the furnace of the apparatus;

FIG. 4 is a scrap vertical section of a furnace incorporated into the apparatus of FIG. 1;

FIG. 5 is a scrap vertical section of a casting head for receiving metal from the furnace of the apparatus and forming a pipe therefrom;

FIG. 6 is a flow chart illustrating processing steps in use of the apparatus of FIG. 1;

FIG. 7 is a diagrammatical side view of another apparatus constructed in accordance with the invention; and

FIG. 8 is a plan view of the apparatus of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The apparatus 300 shown in FIG. 1 is in the form of a transport vehicle and is arranged for movement over a ground surface 308 to excavate earth 310 so as to form a trench 314. Pipe 306 formed by the apparatus is laid in the trench 314 as the apparatus traverses the ground surface 308.

Apparatus 300 has a support frame 316 to which are mounted pairs of side by side tractor drives 318 for moving the apparatus over the ground surface 308.

At a forward location, a control cabin 302 is provided from which the operation of the apparatus is controlled by one or more operators. Also at the forward end, the apparatus has a rotary digger 320 for excavating earth to form the trench 314.

At the rear, apparatus 300 has a plasma arc furnace 340 for producing molten metal from materials in hoppers 322, 324, 326 at the forward end of the apparatus. The molten metal is fed from the furnace 340 to a casting head 342 at the rear of the apparatus and from which the pipe 306 is extruded into the trench 314.

FIG. 2 illustrates components of the apparatus 300 concerned with the transfer of flowable components to the hoppers 322, 324, 326. This shows an open hopper 344 which is carried by frame 316 at a side location to permit transfer of materials in flowable form while the apparatus 300 is moving, such as from a truck travelling side by side with the apparatus. Material 354 loaded into the hopper 344 is transported vertically by a screw conveyor 366 and then horizontally and rearwardly by a screw conveyor 368. Screw conveyor 368 runs along the tops of the hoppers 322, 324, 326 and material transported therealong can be selectively fed to predetermined ones of the hoppers 322, 324, 326, by activation of slide valves 348, 350, 352. Thus, material for the hopper 322 may be first loaded into the hopper 344 and transported into hopper 322 with valve 348 open, then material for the hopper 324 loaded into the hopper 326 and transported to the hopper 324 with valve 350 in its open condition and material for hopper 352 then loaded into the hopper 344 and transported into the hopper 326 with the valve 352 open. To prevent erroneous loading when one valve 348, 350, 352 is open as last mentioned, the other two valves are closed. When it is required to feed material from the hoppers 322, 324, 326 valves 360, 362, 364 at lower outlets from the respective hoppers 322, 324, 326 are selectively operated. These valves open to a horizontal screw conveyor 375, which then transports materials away from the hoppers, generally rearwardly.

As shown in FIG. 3, screw conveyor 375 communicates with an upper end of a rotary kiln 390. Kiln 390 has hollow cylindrical element 392 mounted for rotation about a slightly inclined axis by rollers 394. Fixed end elements 398, 400 enclose the respective ends of the element 392, slidingly. The cylindrical element 392 is in use rotated about its axis by a motor 410 which drives a spur gear 415 coupled to an external peripheral gear 414 on the element 392. End element 398 communicates via a duct 405 with the upper part of the furnace 340, for delivery of material from the rotary kiln 390 to the furnace 340.

The furnace 340 is formed in the manner described in our Australian Patent Application No. 2005904332 filed 11 Aug. 2005 and our Australian Patent Application entitled “Improved Smelting Furnace”, filed the same day as the present application. The contents of these specifications are hereby incorporated into the present specification to form part thereof.

The following is a brief description of the furnace 340. For a fuller understanding of its operation, reference should be made to the mentioned patent specifications.

The furnace 340 has a double walled metal vessel 420 having a highly polished dome-like interior upper surface 422. Cooling liquid, such as liquid sodium, is circulated in the space between the two walls of vessel 420 for cooling the vessel. Material in duct 405 is delivered centrally at the top of the vessel 420 into an internal chamber 424 thereof via an electrode forming head 412, more particularly through a central upright opening 425 in the head 412. A hollow cylindrical electrode 426 of carbonaceous material is formed by downwards extrusion from the head 412 between parallel concentric annular walls 428 which extend downwardly from the head 412. Particulate carbonaceous material and liquid pitch for forming the electrode 426 are fed to the head 412 via ducts 430, 432.

A lower electrode 440 is formed in the base of the vessel 420 in internal chamber 424. As material from the kiln 390 is passed down through the head 412, it falls down the hollow interior of the electrode 426 to accumulate on the floor of the interior of the furnace. Inert gas, such as argon, is passed into the chamber 424 via a central downwardly extending pipe 427 within the electrode 426. Means (not shown) is provided for applying DC electric potential across the electrodes 426, 440, with electrode 426 as a cathode and electrode 440 as an anode. By this application of electric potential, the introduced gas in the furnace from pipe 427 is ionised to form a plasma and the material introduced into the vessel 420 is heated to a high temperature, aided by the internal reflective surface 422 of the vessel 420. As a result, the material in the furnace is smelted. Resultant liquid slag 442 is removed from vessel 420 via an outlet 444, and resultant molten metal 446 accumulating at the bottom of the interior of the vessel 420 is removed via an outlet 448.

Off gas formed during smelting in furnace 340 is removed from the furnace via an upper pipeline 450 and fed back into the cylindrical element 392 of kiln 390, at the lower end thereof, to pass upwardly through the element 392 to exit the kiln via an upper outlet duct 452. A fan 460 may be provided to facilitate this passage of the off gas through the kiln 390.

The hot off gas passed through the kiln 390 serves to preheat the material passing therethough to the furnace 340. The off gas passes from the kiln 390 at the upper end thereof via a duct 452.

The casting head 342 is shown in more detail in FIG. 5. The head 342 includes a hollow cylindrical but axially curved outer mould 370 which is of annular cross-section having a hollow curved cylindrical interior with an inlet 372 and an outlet 374 for circulating cooling liquid such as water through the interior of the mould 370 to cool the mould. The coolant liquid is circulated by a pump 382 and passes through a heat exchanger 380. Cooler liquid is supplied to the heat exchanger 380 via pipes 386, which lead to a suitable coolant reservoir 388 carried by frame 316 of the apparatus 300. The cooler liquid may be circulated through the heat exchanger 380 in any suitable way, such as by use of a pump 389.

The casting head 342 has a central internal mould element 395 which is of cylindrical form, being positioned in the mould 370 towards the inlet end thereof. It is positioned with its periphery spaced inwardly from the inner periphery of the mould 370 by a distance equal to the intended wall thickness of the pipe 306.

Molten metal 446 for furnace 340 passes into mould 370 from furnace outlet 448, passing between the element 395 and the inner periphery of the mould 370. Accordingly, the molten metal is conformed to an annular cross-sectional shape which, by action of the coolant circulated through the mould 370 is maintained as the metal passes through mould 370. The so formed tubular structure of the metal introduced into the mould 370 is maintained as it passes through the mould 370. At exit from the mould 370, the metal is still quite hot and can be bent. The so formed hot pipe 306 passes between sets of rollers 396 to bend the pipe 306 from the somewhat vertical orientation adopted as the pipe emerges from the mould 370 to a substantially horizontal state. The pipe is progressively deposited at the bottom of the trench 314, as the apparatus 300 moves along ground surface 308.

The preheating of material passing through kiln 390, by action of the hot off gas through the kiln, facilitates operation of the furnace 340. The off gas, after passing into the duct 452 at the upper end of the kiln passes along duct 452 and, as shown in FIG. 2, successively through the interiors of hoppers 322, 324, 326. The still hot off gas in the duct 452 thus serves to heat the duct 452 and preheat the materials in the hoppers 322, 324, 326.

After leaving the hopper 326, duct 452 conveys off gas to processing apparatus carried by the frame 316 of the apparatus 300 and which is illustrated diagrammatically only in FIG. 6. In particular, the off gas passes to a precipitator 142 which separates fine metal dust, carbon and ash therefrom as shown in step 180 in FIG. 6. The retrieved material is passed to a magnetic separator 182 which separates metals therefrom and returns it via a return duct 510 (FIG. 1) to the hoppers 322, 324, 326. Carbon ash 190 is also separated at this step and is then passed to a mechano fuser 192 to then be fed to the head 412, together with graphite powder 212. In the head 412 these materials are mixed and heated, by heat from the furnace interior, to form the electrode 426. The heated and mixed material then passes as previously described between the hollow cylindrical walls 428 in the furnace 340 to form the electrode 425 by downwards extrusion.

Material separated from the fine metal dust, carbon and ash in the precipitator 142 is passed to a vortex scrubber 505, which also receives micronised limestone 511. From the vortex scrubber 505, there emerges clean air 507 and separated limestone slurry 509. Slurry 509 has entrapped materials such as sulphur and superfine gases or dust. The slurry may be retained in a suitable receptacle on the apparatus 300 and periodically removed for separate disposal.

Power for the apparatus 300, for driving the tractor drives 318 and otherwise for operating the apparatus 300, may be derived from one or more motor driven generators, such as diesel generators, mounted on the apparatus.

The materials from which the pipe 306 is formed may be varied, depending on requirements. In a typical application, the material may comprise metal in the form of powder or of granular or similar form, stored in hopper 322, a suitable flux material in particulate form such as limestone; stored in hopper 324, and a suitable reductant such as granular coal or coke, stored in hoppers 326. By this, the resultant smelted material for forming the pipe 306 is iron or a suitable alloy containing iron.

In a modification (not shown) there may be more than one furnace 340, with storage and transport arrangements made for supply of differing mixes of constituents thereto. For example, the apparatus may be arranged to feed the casting head 342 with metals of different compositions, derived from separate furnaces 340, such that metals of different compositions are extruded one around the other. By this, an inner portion of the pipe 306 may have one metallic composition and the outer part thereof another metallic composition.

The invention may be adapted to lay elongate elements other than pipes. For example, FIGS. 7 and 8 show a modified apparatus for laying spaced side by side rails 472 on sleepers 474 to form a rail line. Apparatus 408 is generally similar to apparatus 300. In particular, the arrangements for storage and handling of the materials for forming molten metal and transporting these, and the arrangement of the furnace 340 may be generally the same as in the apparatus 300. In this case, however, three casting heads 402, 404, 406 are provided instead of the single casting head 342. These are arranged for continuous casting of metal. Heads 402, 404 are positioned side by side on the apparatus 408 for continuously casting the rails 472, with head 406 being centrally disposed for casting a metal section for forming the sleepers 474. These heads 402, 404, 406 may be fed from separate furnaces like furnace 340, or fewer furnaces, such as a single furnace, may be employed.

In this case, the cast metal to form the rails and the sleepers is formed at the forward end of the apparatus 408, and the apparatus, instead of having tractor drives 318, has wheels 476 which a driven by a suitable motor to enable the apparatus 400 to run on the rail line as it is formed.

The metal section 462 which is extruded by head 406 is cut into sleeper length sections 462 by a suitable cutting means such as a metal saw (not shown) and then transported (by means not shown) forwardly on the apparatus to the front of the apparatus where the lengths are grasped by a swingable mechanical arm and successively laid transversely on the ground at the front the apparatus 408 to form the sleepers 474, and such that the rails 472 are laid on the sleepers as the apparatus moves along the already laid rail line.

The sleepers may be extruded in a suitable cross-section such as the section shown in FIG. 8, or may be extruded as, for example, flat section which is stamped (by means not shown) to form the desired cross-section.

Means (not shown) may be provided for securing the rail to the sleepers as the apparatus 400 progresses. Thus, welding heads may be provided for this purpose so as to weld the sleepers to the rails, or apparatus may be provided for drilling the sleepers, possibly before laying, and for subsequently securing the sleepers to the rails by use of conventional rail fasteners.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The described arrangements have been advanced merely by way of explanation and many modifications may be made thereto without departing from the spirit of the scope of the invention which includes every novel feature herein disclosed.

LIST OF PARTS

-   Precipitator 142 -   Fine Metal Dust Carbon and Ash 180 -   Magnetic Separator 182 -   Carbon Ash 190 -   Mechano Fuser 192 -   Graphite Powder 212 -   Apparatus 300 -   Control Cabin 302 -   Ground Surface 308 -   Earth 310 -   Trench 314 -   Pipe 306 -   Support Frame 316 -   Tractor Driver 318 -   Rotary Digger 320 -   Hopper 322, 324, 326 -   Plasma Arc Furnace 340 -   Casting Head 342 -   Open Hopper 344 -   Slide Valve 348, 350, 352 -   Material 354 -   Screw Conveyer 366,368, 375 -   Outer Mould 370 -   Inlet 372 -   Outlet 374 -   Heat Exchanger 380 -   Pump 382 -   Pipe 386 -   Coolant Reservoir 388 -   Pump 389 -   Rotary Kiln 390 -   Hollow Cylindrical Element 392 -   Roller 394 -   Mould Element 395 -   Rollers 396 -   Fixed End Element 398, 400 -   Casting Head 402, 404, 406 -   Duct 405 -   Apparatus 408 -   Motor 410 -   Electrode Forming Head 412 -   External Peripheral Gear 414 -   Spur Gear 415 -   Double Walled Metal Vessel 420 -   Highly Polished Dome-Like Interior Upper Surface 422 -   Internal Chamber 424 -   Electrode (Cathode) 426 -   Pipe 427 -   Parallel Concentric Annular Walls 428 -   Duct 430,432 -   Electrode (Anode) 440 -   Slag 422 -   Outlet 444, 448 -   Molten Metal 446 -   Upper Piper 450 -   Upper Outlet Duct 452 -   Fan 460 -   Metal Section 462 -   Rail 472 -   Sleeper 474 -   Wheel 476 -   Return Duct 510 -   Vortex Scrubber 505 -   Clean Air 507 -   Limestone Slurry 509 -   Micronised Limestone 511 

1. Apparatus for laying an elongate member, the apparatus comprising means for continuous forming the elongate member, and means for laying the elongate member as it is formed and as the apparatus travels on a ground surface.
 2. Apparatus as claimed in claim 1 including means for forming molten material and means for forming the elongate member therefrom.
 3. Apparatus as claimed in claim 1 wherein the means for forming forms the elongate member by continuous forming.
 4. Apparatus as claimed in claim 3 wherein the means for forming forms the elongate member by continuous casting.
 5. Apparatus as claimed in claim 2, comprising means for storing in flowable form the material or at least one component for forming the material.
 6. Apparatus as claimed in claim 4, comprising means for delivering the material or said component, in flowable form, to the means for forming molten material and for delivering of the molten material to mold means for casting the elongate member therefrom.
 7. Apparatus as claimed in claim 4, wherein the apparatus for forming is in the form of a furnace for forming the material as metal.
 8. Apparatus as claimed in claim 7 wherein the furnace is a plasma arc furnace.
 9. Apparatus as claimed in claim 1, wherein the elongate member is a pipe.
 10. Apparatus as claimed in claim 9, further including excavating means for forming a trench into which the pipe is laid by the apparatus.
 11. Apparatus as claimed in claim 1 wherein the elongate member is a rail.
 12. Apparatus as claimed in claim 11 wherein the apparatus is arranged to lay the rail forwardly of the apparatus, the apparatus being adapted to run on the laid rail during said laying.
 13. A method of laying an elongate member, comprising: continuously forming the elongate member on a transport vehicle, and laying the elongate member using the transport vehicle as the transport vehicle travels.
 14. The method of claim 13 including forming material in molten form and forming the elongate member by casting of the molten material.
 15. The method of claim 14 wherein the elongate member is continuously cast.
 16. The method of 14 wherein the molten material is delivered to a casting head to form the elongate member.
 17. The method of claim 13 wherein the material, or at least one component for forming the material, is stored in particulate or other flowable solids form on the transport vehicle, prior to causing the material to be formed in the molten state.
 18. The method of claim 14 wherein the molten material is metal.
 19. The method of claim 18 wherein the material is formed by smelting.
 20. The method of claim 19 wherein the smelting is effected by use of a plasma arc furnace.
 21. The method of claim 13 wherein the elongate member is a pipe.
 22. The method of claim 13, further comprising laying an elongate member in an excavated trench.
 23. The method of claim 22, wherein the trench is formed by excavation means on the transport vehicle.
 24. The method of claim 13 wherein the elongate member is a rail.
 25. The method of claim 24 wherein the rail is laid forwardly of the vehicle, and the vehicle travels on the so laid rail. 26.-27. (canceled) 